My plans are: 1. To continue an analysis of drug effects on the structures in the irido-corneal angle. Ultrastructural changes in the inner wall of Schlemm's canal are investigated by means of scanning electron microscopy. Transmission electron microscopy is used to investigate chamber angle tissue after perfusion of electron dense markers in gelatine. 2. To analyze the permeability of the choroidal capillaries to low molecular weight substances and determine the role of the pigment epithelium in the transport of nutrients from the choroid into the retina. 3. To continue studies on the factors affecting the formation of aqueous humor.